Zika Outbreak Needs Intensive, Rapid Research

International meeting outlines strategy for study

by Michael Smith Michael Smith North American Correspondent, MedPage Today
March 02, 2016

The Zika virus outbreak -- with its possible link to neurological complications both in unborn children and adults -- is a "unique situation" that calls for rapid and intensive research into ways of bringing it under control, a U.S. scientist said.

"We must move extremely quickly" to understand the virus, the consequences of infection, and methods of slowing or stopping transmission, according to Lyle Petersen, MD, of the CDC's division of vector borne-diseases in Fort Collins, Colo.

Currently, "there are literally thousands of infections occurring every single day in the Americas," Petersen told reporters at the end of a two-day scientific meeting called by the Pan-American Health Organization (PAHO) to set a research agenda for the Zika epidemic.

Petersen said in 20 years of studying vector-borne diseases, he has never seen one that appears to be able to infect fetuses and cause congenital malformations in the brain as well as causing neurological complications in adults. It's also the first, he said, that is "readily spread" by sexual means.

"Because this is a unique situation it requires a unique response and this response has to be guided by research," he said.

The meeting, including some 70 scientists from around the world, was intended to set research priorities to deal with the outbreak, according to Marcos Espinal, MD, of the PAHO's communicable diseases and health analysis department.

Among the topics that need urgent attention, he said, are:

Learning the absolute risk that a pregnant woman, infected with Zika, will see an adverse outcome for the baby

Finding ways to detect the virus in the blood

Understanding the virus itself, as well as the consequences of infection

Developing new ways of controlling the main vector, the mosquito Aedes aegypti

Espinal told reporters that Zika has been associated with congenital brain malformations (which have been lumped together as microcephaly, although others have been reported) in Brazil and in French Polynesia, while increased rates of Guillain-Barré syndrome have been reported in both those regions as well as Suriname, Venezuela, Colombia, and El Salvador.

So far, he said, 31 countries in the Americas are reporting Zika epidemics, with more than 135,000 cases reported and 3,000-odd confirmed in the lab. But that number underestimates the extent of the issue, he said, because in 80% of infections there are no signs or symptoms.

Because it is usually mild or asymptomatic, Zika has been a "pretty obscure virus," Petersen noted, with only a handful of research papers since it was first discovered in the middle of the last century.

It's not clear why the virus is now being associated with more serious outcomes, he said.

But the outbreak illustrates the effect of neglecting public health measures and the need to be prepared, he said. In recent years, he said, responses to vector-borne disease -- such as mosquito control programs -- have been allowed to "deteriorate."

But "new things happen and unexpected things happen and we have to be prepared," Petersen said.

He added the evidence is becoming "extremely strong" for a link between Zika and neurological complications in newborns.

For that reason, he said, there should also be research on ways to protect pregnant women, including such things as bednets to prevent mosquito bites, insect repellents, indoor mosquito spraying, and condoms to prevent sexual transmission.

Such products are available, he said. "We just need to figure out is these are acceptable methods that women will actually use in their own countries and whether they actually work," Petersen said.

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